The Performance Analysis And Optimization Of The Distributed Workspace Measuring And Positioning System

The wMPS (workspace Measuring and Positioning System) is a new large-scalecoordinate measurement method based on the spatial constraint of multi-station. It canenlarge the measurement volume without decreasing the accuracy, which benefitsfrom the network measurement principle. Comparing with the total stationmeasurement method, its performance advantages originate from the measurementnetwork, namely, the network structure is the critical factors affecting theperformance advantages of the wMPS. Themed with the performance analysis andoptimization of the wMPS, this dissertation abstracts the three basic factors from theperspective of network. Then starting with these three factors, this dissertationpresents the deep analysis of the wMPS performance, carries out the relevantoptimization methods, and performs the experiments verifying those proposedmethods. The main contents and works are arranged as follows:1. This dissertation analyzes the performance advantages of the wMPS, andfurther abstracts that the network node, the network layout, and the node weights arethe three critical factors in constructing a stable measurement network. Then concreteanalysis and discussion are performed on these three factors in the following pages.2. With respect to the characteristics of the rotating laser beams scanningmeasurement technology which is adopted in a network node (a single transmitter ofthe wMPS), this dissertation carries out the strict analysis on it using the matrixperturbation analysis theory. With the analytical results, this dissertation points outthat the difference of the consecutive scanning angles of the two laser beams are theunique determinant affecting the observing performance. Moreover, this research is atheoretical guider to the optimized application of a single transmitter, and a theoreticalbasis provider of assembly and inclination adjustment of the scanning lasers.3. With respect to the problem of network layout, this dissertation first introducesthe concept of ill posed problems, points out that the ill-conditioned measurementcorresponds to the singularity of a wMPS network, then uses the ill-conditionedanalysis theory to discuss the wMPS layout problem, and gives the sectional resultthat the condition number of the measurement matrix of wMPS quantitativelymeasures the singularity of its layout. To better understanding the condition number, this dissertation deduces its relationship with the mean squared error and intersectionerror ellipsoid, then discusses the dependency between the measurement space and thenetwork layout. For combining with practices, this dissertation studies theoptimization methods for searching the optimal measurement space in a fixed networklayout and constructing the optimal network layout for a fixed measurement space,respectively, then proposes the layout strategy of combining empirical layout andsoftware optimized layout, finally conducts the relevant verifying experiments.4. In view of the nodes weighting problem, and in consideration of the dynamicmeasurement characteristics of the wMPS, this dissertation improves the weighingstrategy in two aspects, one is the weighting object, and the other is the accurateacquirement of weights. For the first, it proposes weighting for the whole laser beams;and for the second, it proposes dynamically computing the accurate weights using thelocal control network. Then, based on the above analysis, it conducts the experiments,the results of which indicate that the proposed weighting method can significantlyimprove the measurement accuracy of the interested area.5. Important engineering application study. Backgrounded with the applicationsof airplane level measurement and the accuracy improvement of an industrial robot,this dissertation implements the optimized application of the wMPS using the abovetheoretical results. First, the airplane level measurement is accomplished throughconstructing the optimized layout of the wMPS and the dynamically weightingmethod. Along with the distributed measurement software, several airplanes areeffectively measured. Then, in view of the absolute accuracy improvement problem ofan industrial robot, this dissertation proposes the modeling process of integrating thewMPS with the industrial robot in the first time, and performs the accuracyimprovement combining with those proposed methods.